CVE 2006-6056
Linux kernel 2.6.x up to 2.6.18 and possibly other versions, when SELinux hooks are enabled, allows local users to cause a denial of service (crash) via a malformed file stream that triggers a NULL pointer dereference in the superblock_doinit function, as demonstrated using an HFS filesystem image.
See the 
CVE page on Mitre.org
for more details.
